The invention is applicable to plug-in modules of any size that can be inserted into module racks, of the kind often used to make up electronic and electrical equipment. The plug-in modules and guide rails are disposed both next to and one above one other in a module rack.
Each plug-in module is connected to the module rack with the aid of multipin plug connectors. Knife strips and spring strips are used which are equipped with up to ninety six spring contacts. Inserting such three-row plug connectors requires strong forces, and this is especially true when the plug-in modules are to be removed, or pulled out, from the module rack. Without suitable aids, plug-in modules are thus almost impossible to remove from the module racks.
Various embodiments of lever systems with actuating handles are known as aids in the insertion and removal of plug-in modules. These systems are disposed in the region of both the bottom and the top of the front panel of the plug-in module to be inserted or removed.
In one of these systems, a bell crank has a protrusion that engages a recess of a strip provided on the front of the profile rail of the module rack and that thus serves as an aid in the insertion and removal of the plug-in module. Because of the shortness of the lever arm between the above protrusion and the pivot axis of the bell crank, however, which shortness is dictated by structural requirements necessary to meet standards, the forces that can be exerted on the plug-in module upon actuation of the lever system are limited, and as a result, the static friction between the springs and knives of the plug connectors that must be overcome when beginning to remove the plug-in module can be overcome only with considerable effort.